display.rb

class DisplayTodos
  
  def print_task_list(list)
    list.tasks.each do |list_item|
      puts "#{list_item.id}. #{list_item.description} #{list_item.is_complete ? "Completed: Yes" : "Completed: No"}."
    end
  end

  def start_program
    puts "Type the filename of the list you want to load."
  end

  def option_list
    puts "Options: Type 'list' to see your to do list,
          'add' to add a task,
          'delete' to delete a task,
          'complete' to mark a task completed,
          'q' to exit. "
  end

  def add_item_prompt
    puts "What do you want to add?"
  end

  def delete_item_prompt
    puts "What numbered item do you want to delete?"
  end

  def mark_complete_prompt
    puts "What numbered item did you complete today?"
  end

end

todo.csv

Move with Lil to the black mountain hills of Dakota
Lose Lil to Danny
Get hit in the eye by Danny
Walk into town seeking revenge
Book room at local saloon
Check into room and read Gideon's bible
Drink too much gin
Overhear Lil and Danny in neighboring room
Burst into neighboring room and declare a showdown
Get shot by Danny and collapse in corner
Visit doctor
Return to room and read Gideon's bible
Sing along! D'do d'do d'do do do d'do d'do d'do

todo.rb

require_relative 'todo_model'
require_relative 'display'

class ToDoController

  def initialize
    @list = ToDoList.new
    @list_view = DisplayTodos.new
    load_list
    task_manager
  end

  def load_list
    @list_view.start_program
    load_list = gets.chomp
    if load_list.end_with? ".txt"
      @list.convert_to_csv(load_list)
    elsif load_list.end_with? ".csv"
      @list.load_csv('new_todo.csv')
    end 
     @list_view.print_task_list(@list)
  end

  def task_manager
    begin
      @list_view.option_list   
      response = gets.chomp
      if response == 'add'
        @list_view.add_item_prompt
        add_task = gets.chomp
        @list.add_new(add_task)
      elsif response == 'delete'
        @list_view.delete_item_prompt
        delete_task_id = gets.chomp
        @list.delete_task(delete_task_id.to_i)
      elsif response == 'complete'
        @list_view.mark_complete_prompt 
        mark_id_complete = gets.chomp
        @list.complete_task(mark_id_complete.to_i)
      end
      @list_view.print_task_list(@list)
    end until response == "q"
  end
end

ToDoController.new

todo_model.rb

require 'pry'
require 'csv'

class Task
  attr_accessor :id, :description, :is_complete

  def initialize(id, description, is_complete = false)
    @id = id
    @description = description
    @is_complete = is_complete
  end

  def is_complete?
    @is_complete
  end
end

class ToDoList

  def initialize
    @all_tasks = []
  end

  def add_new(task_name, complete = false)
    @all_tasks << Task.new(@all_tasks.length + 1, task_name, complete)
  end

  def tasks
    @all_tasks
  end

  def delete_task(task_id)
    @all_tasks.delete_if { |task| task.id == task_id }
  end

  def complete_task(task_id)
    @all_tasks.each { |task| task.is_complete = true if task.id == task_id}
  end

  def load_txt(filename)
    File.open(filename).each_line { |line| add_new(line.chomp)}
  end

  def save_as_csv(filename)
    CSV.open(filename, "wb") do |csv|
      @all_tasks.each do |task|
        csv << [task.id, task.description, task.is_complete]
      end
    end
  end

  def convert_to_csv(filename)
    self.load_txt(filename)
    self.save_as_csv('new_todo.csv')
    self.load_csv('new_todo.csv')
  end

  def load_csv(filename) 
    CSV.foreach(filename) do |row| 
      add_new(row[1], (row[2] == "true") ) 
    end
  end
end